| 摘要 |
A miniature helical scan video tape recorder (VTR) utilizes a reduced-diameter guide drum, but the video signals recorded thereby onto the tape have a standard track pattern and can be reproduced using a standard VTR having a guide drum of standard diameter D1. In the miniature VTR, the tape is wrapped for a tape wrap angle alpha (e.g., substantially 300 degrees) at a still angle theta 2, whereas the standard VTR uses a wrap angle of 180 DEG and a still angle of theta 1. In order to ensure that the miniature VTR achieves the same record track length l'N and recording angle theta 0 as the standard VTR, the diameter D2 of the miniature VTR is selected to satisfy the equation <IMAGE> where fV is the video field frequency. The still angle theta 2 satisfies the equation <IMAGE> the video signal to be recorded is given a non-standard horizontal scanning frequency f'H according to the relation <IMAGE> where fH is the standard horizontal scanning frequency. The recording head can be provided with two gaps for double-azimuth recording of the video signal. |
